U.S. patent number 8,248,948 [Application Number 11/823,949] was granted by the patent office on 2012-08-21 for monitoring network conditions of a wireless network.
This patent grant is currently assigned to Tropos Networks, Inc.. Invention is credited to Cyrus Behroozi, Mukesh Gupta, Amit Saha, Devabhaktuni Srikrishna, Kevin Weil.
United States Patent |
8,248,948 |
Weil , et al. |
August 21, 2012 |
Monitoring network conditions of a wireless network
Abstract
A method of determining a location of a network condition within
a wireless mesh network is disclosed. The method includes a test
device testing a first plurality of wireless hops of the wireless
mesh network. The test device also tests a second number of
wireless hops of the wireless mesh network. The test device locates
the network condition within the wireless mesh network by comparing
the test of the first plurality of wireless hops with the test of
the second number of wireless hops.
Inventors: |
Weil; Kevin (Redwood City,
CA), Gupta; Mukesh (Milpitas, CA), Saha; Amit
(Sunnyvale, CA), Behroozi; Cyrus (Menlo Park, CA),
Srikrishna; Devabhaktuni (Sunnyvale, CA) |
Assignee: |
Tropos Networks, Inc.
(Sunnyvale, CA)
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Family
ID: |
39826792 |
Appl.
No.: |
11/823,949 |
Filed: |
June 29, 2007 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20080247317 A1 |
Oct 9, 2008 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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60921761 |
Apr 3, 2007 |
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Current U.S.
Class: |
370/237 |
Current CPC
Class: |
H04L
43/50 (20130101); H04L 43/0852 (20130101); H04L
43/0888 (20130101); Y04S 40/168 (20130101); Y04S
40/00 (20130101); H04L 41/5003 (20130101); H04L
43/0864 (20130101) |
Current International
Class: |
G01R
31/08 (20060101) |
Field of
Search: |
;370/241,241.1,242,245,252,216 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Blohm & Voss, Pipe Handling Equipment, Drill Pipe spinner,
2004. 2pp. cited by other .
Oil Country Manufacturing, Inc., General Catalog, 2005, Cover Page
and 5 pp. cited by other.
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Primary Examiner: Yao; Kwang B
Assistant Examiner: Liu; Jung-Jen
Attorney, Agent or Firm: Short; Brian R.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION(S)
The present application is based on and claims the benefit of U.S.
Provisional Patent Application Ser. No. 60/921,761, entitled
"Quantifying End User Experience", filed on Apr. 3, 2007, the
disclosure of which is hereby incorporated by reference in entirety
for all purposes.
Claims
What is claimed:
1. A method of determining a location of a network condition within
a wireless mesh network, comprising: a test device wirelessly
connected directly to an access node of the wireless mesh network
testing a first plurality of wireless hops of the wireless mesh
network, the first plurality of hops including a wireless hop
between the test device and the access node, comprising sending a
probe packet from the test device to a first target device located
the first plurality of wireless hops from the test device, and
receiving a probe packet back from the first target device; the
test device testing a second number of wireless hops of the
wireless mesh network, comprising sending another probe packet from
the test device to a second target device located the second number
of wireless hops from the test device, and receiving a probe packet
back from the second target device; wherein a number of the first
plurality of wireless hops is different than the second number of
wireless hops; the test device locating a latency network condition
within the wireless mesh network by comparing a round trip travel
time of the probe packet of the first device with a round trip
travel time of the probe packet of the second device, wherein the
testing the first plurality of wireless hops comprises testing at
least one of a upstream latency, downstream latency, upstream
throughput, downstream throughput, a number of packet retries,
packet success probability, reverse packet success probability and
antenna asymmetry of at least one of the first plurality of
wireless hops.
2. The method of claim 1, wherein the testing the second number of
hops comprises testing at least one of a latency, a throughput, a
number of packet retries, packet success probability, reverse
packet success probability and antenna asymmetry of the second
number of hops.
3. The method of claim 1, wherein the testing device emulates a
client device connected to the wireless mesh network.
4. The method of claim 1, wherein the testing device emulates an
access node connected to the wireless mesh network.
5. The method of claim 1, the first plurality of wireless hops and
the second number of wireless hops are upstream wireless hops
relative to the test device.
6. The method of claim 1, the first plurality of wireless hops and
the second number of wireless hops are downstream wireless hops
relative to the test device.
7. The method of claim 1, further comprising the test device
determining wireless network parameters including at least one of
receive signal strength, receive signal SNR, transmission retries,
upstream data throughput, downstream data throughput, latency, and
available air-time.
8. The method of claim 7, further comprising: triggering an alert
if at least one of the wireless network parameter exceeds or falls
below a threshold.
9. The method of claim 8, wherein the alert comprises communicating
with a network manager.
10. The method of claim 1, further comprising the test device
communicating the location of the network condition to another
device within the wireless mesh network.
11. The method of claim 10, wherein the other device comprises at
least one of a wireless mesh gateway, a wireless mesh access node
or a management server.
12. The method of claim 10, further comprising the other wireless
device modifying wireless network characteristics to mitigate the
network condition.
13. The method of claim 12, wherein the wireless network
characteristic is at least one of routing selection, transmission
channel selection, transmission power, transmission bit rate,
packet QoS, dis-associating a client.
14. The method of claim 1, further comprising the test device
correlating the network condition with other activity of the
wireless mesh network.
15. The method of claim 14, wherein the other activity comprises at
least one of: a routing path selection, a device channel selection,
a device cluster selection.
16. The method of claim 1, further comprising the test device
correlating the network condition with other conditions of the
wireless mesh network.
17. The method of claim 16, wherein the other condition comprise at
least one of: a device within the wireless network experiencing
heaving loading, a hidden node condition, limited availability of
air-time.
18. A test device wirelessly connected to an access node of a
wireless mesh network, the test device operate to: test a first
plurality of wireless hops of the wireless mesh network, the first
plurality of hops including a wireless hop between the test device
and the access node, comprising sending a probe packet from the
test device to a first target device located the first plurality of
wireless hops from the test device, and receiving a probe packet
back from the first target device; test a second number of wireless
hops of the wireless mesh network, comprising sending another probe
packet from the test device to a second target device located the
second number of wireless hops from the test device, and receiving
a probe packet back from the second target device; wherein a number
of the first plurality of wireless hops is different than the
second number of wireless hops; locate a latency network condition
within the wireless mesh network by comparing a round trip travel
time of the probe packet of the first device with a round trip
travel time of the probe packet of the second device, wherein the
testing the first plurality of wireless hops comprises testing at
least one of a upstream latency, downstream latency, upstream
throughput, downstream throughput, a number of packet retries,
packet success probability, reverse packet success probability and
antenna asymmetry of at least one of the first plurality of
wireless hops.
Description
FIELD OF THE DESCRIBED EMBODIMENTS
The described embodiments relate generally to wireless
communications. More particularly, the described embodiments relate
to a method and apparatus for monitoring network conditions of a
wireless network.
BACKGROUND
Wireless networks typically allow a wireless device to connect to
the wireless networks through a base station or access point that
is wired to the network. Wireless mesh networks can additionally
include access points that are wirelessly connected to the network.
The wireless device can transmit data packets that are received by
the base station or access point and then routed through the
network. The wireless network can include many base stations or
access points that are each wired to the network.
Due to the interconnectivity of many devices within a wireless mesh
network, activities and conditions of devices within a wireless
mesh network can greatly influence the operation of other devices
within the mesh network. For example, load imbalances in one area
of a mesh network can adversely affect the operation of the mesh
network at other locations. Additionally, channel selections and
routing path selections of devices can adversely affect the
operation of other devices within the mesh network.
Wireless networks include wireless links that are susceptible to
interference. Wireless mesh networks typically include many
wireless links, and therefore, can be particularly susceptible to
interference. One form of interference is self interference, in
which a wireless link within the wireless mesh network receives
interfering signals from other wireless links of the wireless mesh
network. As packets are relayed through the wireless mesh network,
they can suffer from the effects of self-interference, and/or they
may cause self-interference for other links within the wireless
mesh network.
The self-interference can limit the air-time availability to nodes
of a wireless network. That is, the self-interfering signals of a
node within a wireless network occupy transmission air-time,
thereby limiting the transmission air-time available to other nodes
of the wireless network. Nodes that have poor quality wireless
links can be particularly problematic because they typically
require low-order modulation formats, and packet re-transmissions.
Lower order modulation formats and re-transmissions can both cause
the air-time per bit efficiency to drop, resulting in the
occupation of more air-time, and therefore, adversely affecting
other nodes.
It is desirable to have a method and apparatus for monitoring
conditions of a wireless network. It is additionally desirable to
be able to locate network conditions, and correlate conditions and
activities of the wireless network with operating parameters of the
wireless network.
SUMMARY
An embodiment includes a method of determining a location of a
network condition within a wireless mesh network. The method
includes a test device testing a first plurality of wireless hops
of the wireless mesh network. The test device also tests a second
number of wireless hops of the wireless mesh network. The test
device locates the network condition within the wireless mesh
network by comparing the test of the first plurality of wireless
hops with the test of the second number of wireless hops.
Another embodiment includes a method of a network test device
sensing a network condition. The method includes a wireless network
test device sensing a wireless network parameter, and the wireless
network test device triggering an alert if a wireless network
parameter exceeds or falls below a threshold.
Other aspects and advantages of the described embodiments will
become apparent from the following detailed description, taken in
conjunction with the accompanying drawings, illustrating by way of
example the principles of the described embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an example of a wireless mesh network.
FIG. 2 shows an example of a client test device connected to a
wireless mesh network.
FIG. 3 shows an example of access node test device connected to a
wireless mesh network.
FIG. 4 is a flow chart that shows one example of steps of a method
for determining a location of a network condition within a wireless
mesh network.
FIG. 5 is a flow chart that shows one example of steps of a method
of a network test device sensing a network condition.
DETAILED DESCRIPTION
The embodiments described provide methods of locating network
conditions of wireless networks. Additionally, wireless network
parameters can be sensed at one or more locations within the
wireless network, and used to modify operation of the wireless
network. Correlations between wireless network parameters and
activities and conditions of the network can be used to modify
operation of the wireless network.
The following embodiments and descriptions are directed to wireless
mesh networks. However, it is to be understood that the embodiments
described are not limited to wireless mesh networks. Wireless
networks in general can benefit from the methods of locating and
monitoring network conditions.
FIG. 1 shows an example of a wireless mesh network that includes
gateways 120, 122, 124, access nodes 130-137 and client devices
110-116. The wireless access nodes 130-137 interconnect with each
other, and with gateways 120, 122, 124 to form a mesh.
One embodiment of a gateway originates routing beacons that the
access nodes can use to select routes to at least one gateway based
on a persistence of successfully received routing beacons. The
gateways typically include a backhaul (wired or wireless) to a
wired network 140 that provides access to the internet.
An access node can generally be defined as being a device that a
client device can associated with, and therefore, obtain access to
the mesh network. A gateway can typically operate as an access
node. One embodiment of an access node re-broadcasts successfully
received routing beacons (from either an upstream gateway or access
node).
A client generally can include a laptop computer, a personal
digital assistant (PDA), a cell-phone, or any other device that
includes as interface card adaptable for use with the mesh network
of the invention. The client can access the network though wired or
wireless connections. Wireless clients can access the network
through a MAC (media access control), PHY (physical layer) protocol
such as IEEE 802.11. The 802.11 protocol includes authentication
and association protocols between client devices and the
network.
The access nodes 130-137 form routing paths through the wireless
mesh network. Client devices 110-116 wirelessly connect to any one
of the gateways 120, 122, 124 or access nodes 130-137 to obtain a
data path to the wired network 140. An embodiment of the access
nodes selects routing paths to at least one gateway based on a
persistence of successfully received routing beacons.
The example of a wireless mesh network of FIG. 1 includes the three
gateways 120, 122, 124. Each gateway 120, 122, 124 defines a
cluster. For example, a first cluster of the gateway 120 includes
access nodes 130, 133, 136. A second cluster of the gateway 122
includes access nodes 131, 134. A third cluster of the gateway 124
includes the access nodes 132, 135, 137.
Due to the interconnectivity of mesh network, activities or
conditions of one part of the mesh network can influence the
operation of other parts of the mesh network. Additionally, the
interconnections are wireless links, and therefore, the air-time
occupied by wireless links of each of the access nodes 130-137 and
client device 110-116 can affect the operation of other devices of
the mesh network because there is only a finite amount of air-time
available.
Conditions of a device (gateway or access node) located at one part
of a wireless network can influence the operating of devices
elsewhere within the wireless network. For example, device (gateway
or access node) loading, device routing selections through the mesh
network, bandwidth of the device, latency of the device, channel
selections of the devices and any malfunction of the devices can
all influence the operation of other wireless network devices.
Loading of one device can influence the operation of other devices
because a device that is subject to a large amount of data traffic
(due, for example, to a large client load) can adversely influence
the operating parameters of all devices downstream of the device.
For example, if an access node within the wireless mesh network has
many downstream clients, then the bandwidth available to each
client can be limited. More generally, the bandwidth to all devices
downstream of the heavy-loaded device will be influenced.
Additionally, excessive loading generally occupies large amounts of
air-time, and therefore, also can influence other devices within
the wireless mesh that are not downstream of the device.
Routing selections of one device can influence the operation of
other devices within the mesh network because poor routing
selections can result in poor quality links within a routing path
to a gateway. Poor quality links can cause a host of problems, such
as, low throughput and excessive air-time occupation. Poor link
quality affects the air-time occupied by signals transmitted
through the link because poor links typically require the signals
to have lower-order modulation formats. Therefore, the amount of
air-time occupied per bit goes up. Additionally, poor quality links
typically require more re-transmissions, which also increases the
air-time occupied per bit. If a poor link is located several hops
downstream from a gateway, all of the links between the gateway and
the client device operating on the same or overlapping frequency
additionally occupy air-time as dictated by the last link to the
client device.
Routing selections also influence the loading of devices within the
network, which as previously described, influences other devices.
Routing selections can also influence the latency of data
traffic.
Bandwidth of one device can influence the operation of other
devices because throughput of a device influences all devices
downstream of the device. A limited throughput can also cause more
air-time to be occupied when attempting to maintain a given data
rate. Additionally, a limited throughput will typically cause
additional latency.
Latency of one device can influence the operation of other devices
because excessive latency of a device can slow the operation of all
devices downstream of the device. This can also cause additional
use of air-time.
Depending upon the physical locations of the access nodes, certain
access nodes are more likely to interfere with other nodes of the
wireless network. Neighbor nodes can be defined as other nodes that
can receive signals from a node, wherein the received signals have
a predetermined amount of signal strength. Neighboring nodes can be
a source of self-interference, and can cause the air-time available
to a node to fall below desirable levels.
All wireless communication between the nodes occupies air-time.
Air-time is additionally occupied when client devices 110-115 are
connected to the wireless mesh network. The time occupied by each
client device connection is generally not equal. That is, the
air-time occupied can vary greatly from client device to client
device. Generally, the air-time occupied by a client device is
dependent upon the qualities of the links between the client device
and the gateway the client device is routed to, and the number of
wireless hops (a hop is a wireless link) between the client device
and the gateway. The more wireless hops a link is away from a
gateway, the greater the effect a link can have on the available
air-time capacity. That is, each link between the client device and
the connecting gateway occupies air-time.
Generally, a range exists around an access node (such as access
node 134) in which wireless links within this range can reduce the
air-time available to the access node 134. Medium access protocols
such as IEEE 802.11 implement Carrier Sense Multiple Access with
Collision Avoidance (CSMA/CA). In such protocols, transceivers
sense a channel and defer transmissions while the channel is
considered to be busy. The channel is deemed to be busy if a
received signal exceeds a Clear Channel Assessment Threshold
(CCAT), and the nodes can no longer transmit any signals.
Therefore, if the access node 134 is receiving transmission signals
from at least one of the wireless links within the reception range,
the access node 134 may be unable to either receive or transmit
signals. As such, at some point the available air-time can become
so limited that the access node 134 cannot properly operate within
the wireless mesh network.
Wireless network parameters of each individual device can provide
an indication the operation of the device itself. For example, a
client device or access node within the mesh network has network
parameters, such as, received signal strength, receive signal SNR,
upstream data throughput, downstream throughput (for an access
node), latency, Quality of Service (QoS) and/or available air time,
which provide an indication of the operation of the device. Each of
these network parameters can be influenced by the activities and/or
conditions of other devices within the wireless network.
FIG. 2 shows an example of a client test device 211 connected to a
wireless mesh network. For an embodiment, the client test device
211 monitors wireless network performance information as is
expected to be experienced by a client device associated with the
wireless network. The client test device 211 similarly placed can
be used to locate problems within the wireless network. The client
test device 211 can, for example, alert a network operator 280 of
identified network conditions and the locations of the network
conditions.
One embodiment of the client test device 211 tests multiple hops of
the wireless mesh network to identify a location of a network
condition. The network conditions can include, for example, an
upstream (or downstream) device that is exhibiting behavior that
may be detrimental to the operation of the wireless network. For
example, the device may have excessive upstream latency, excessive
downstream latency, excessive upstream throughput, excessive
downstream throughput, a high number of packet retries per packet,
packet success probability, reverse packet success probability and
antenna asymmetry. The network condition may be degrading the
network performance as experienced by the test client device.
Identification of the location of the network condition can be
valuable information that can be used to eliminate or mitigate the
effects the condition has on the performance of the wireless
network.
One method of locating the network condition includes testing the
condition over a first number of wireless hops and then testing the
condition over a different number of wireless hops. Comparison of
the two tests can provide information regarding the location of the
network condition. One embodiment method of locating the network
condition includes running a trace route test over the two
different numbers of wireless hops.
One embodiment of a latency network condition test includes sending
a probe packet from the test device to a first target device
located a first number of wireless hops from the test device,
having the first target device send a probe packet back to the test
device, and measuring the round trip travel time of the probe
packets. The test device can locate latency network conditions by
then sending another probe packet from the test device to second
target device located a second number of wireless hops from the
test device, and comparing the round trip travel time for probe
packets of the first and second target devices.
One embodiment of a throughput (upstream) network condition test
includes sending as many data packets as possible during a
predetermined length of time (for example, 2 seconds) from the test
device to the first target device located the first number of hops
away, and measuring the number of packets sent. Packets that fail
to be received by the first target device are retried (transmitted
again) because an acknowledgement (ACK) is not received. The
measured number of packets sent is multiplied by the bytes/packet,
and divided by the predetermined length of time to obtain the
throughput between test device and the first target device. The
same process repeated with the second target device located the
second number of wireless hops away from the test device to obtain
the throughput between the test device and the second target
device.
A downstream throughput test can be testing using methods similar
to the upstream throughput test. However, the first and second
target devices can be instructed to send as many data packets as
possible during the predetermined length of time (for example, 2
seconds) from the target devices to the test device. Packets that
fail to be received by the test device are retried (transmitted
again) because an acknowledgement (ACK) is not received. The
measured number of packets sent is multiplied by the bytes/packet,
and divided by the predetermined length of time by both the first
target device and the second target device to obtain the throughput
between target devices and the test device.
One embodiment of a packet retry network condition test includes
the test device transmitting, for example, 802.11 protocol unicast
packets. The unicast packets must receive an ACK, otherwise, the
unicast packets are resent (retried). The number of retries can be
counted for unicast packets sent to both the first target device
and the second target device. The results can be compared to locate
a network condition.
Other network conditions can include parameters that reflect link
qualities of links within paths between the test device and the
first and second target devices. For example, signal strength
(received), noise (for example, SNR), packet success probability
(typically, in the downstream direction), reverse packet success
probability (typically, in the upstream direction) and antenna
asymmetry (typically measured by comparing the signal quality (by,
for example, measuring the success rate of received packets) of
signals of more than one antenna of the device) of a device can all
be monitored by the devices within the upstream and downstream
paths. The test device can request these link quality parameters
from the first and second target devices, allowing the test device
to locate network conditions related to link quality
parameters.
An exemplary embodiment can include detecting an air-time capacity
problem, and then modifying operation of other devices to mitigate
the air-time capacity problem. The embodiments of controlling
air-time include sensing an air-time availability problem, and
taking steps to reduce the problem. Other embodiments include
taking steps to help ensure that air-time availability problems
don't occur.
FIG. 3 shows an example of network node test device 335 connected
to a wireless mesh network. For an embodiment, the node test device
335 monitors wireless network performance information as expected
to be experienced by a similarly placed node of the wireless
network.
Fundamentally, the node test devices can operate at a higher
transmit power than the client test devices. The node test devices
are located within the wireless mesh network, and can have both
upstream and downstream paths. Additionally, node test devices can
be placed at a higher elevation (typically, for example, at the top
of a street light) than the client test devices. All of these
differences can change the network conditions experienced by the
test devices.
One embodiment of the node test device 335 tests multiple hops of
the wireless mesh network to identify a location of a network
condition. The network condition can include, for example, an
upstream (or downstream) device that is exhibiting behavior that
may be detrimental to the operation of the wireless network. For
example, the device may have excessive upstream latency, excessive
downstream latency, excessive upstream throughput, excessive
downstream throughput, a high number of packet retries per packet,
packet success probability, reverse packet success probability
and/or antenna asymmetry. The network condition may be degrading
the network performance as experienced by the node test device.
Identification of the location of the network condition can be a
valuable piece of information that can be used to eliminate or
mitigate the effects the condition has on the performance of the
wireless network.
One method of locating the network condition includes testing the
condition over a first number of wireless hops and then testing the
condition over a different number of wireless hops. Comparison of
the two tests can provide information regarding the location of the
network condition. One embodiment method of locating the network
condition includes running a trace route test over the two
different numbers of wireless hops.
The methods of determining network condition latency, throughput
(upstream and upstream), packet retries (upstream and downstream),
signal strength, noise, packet success probability (forward,
reverse, upstream and downstream), an antenna asymmetry tests for
the node test device can be similar to the client test device
methods previously described. One fundamental difference, however,
is that the node test devices typically have downstream target
devices as well.
FIG. 4 is a flow chart that shows one example of steps of a method
for determining a location of a network condition within a wireless
mesh network. A first step 410 includes a test device testing a
first plurality of wireless hops of the wireless mesh network. A
second step 420 includes the test device testing a second number of
wireless hops of the wireless mesh network. A third step 430
includes the test device locating the network condition within the
wireless mesh network by comparing the test of the first plurality
of wireless hops with the test of the second number of wireless
hops.
The testing the first plurality of wireless hops and/or testing of
the second number of hops can include testing at least one of a
upstream latency, downstream latency, upstream throughput,
downstream throughput, a number of packet retries, packet success
probability, reverse packet success probability and antenna
asymmetry of at least one of the first plurality of wireless
hops.
The testing device emulates a client device connected to the
wireless mesh network, or the testing device emulates an access
node connected to the wireless mesh network. The testing device
emulating a client device is typically connected to an upstream
access node. The testing device emulating an access node can be
wirelessly connected to at least one upstream gateway or access
node, and can include any number of downstream access nodes and/or
client devices. The test device can test any number of upstream or
downstream wireless hops.
Embodiments of the test device can determine wireless network
parameters including receive signal strength, receive signal SNR,
transmission retries, upstream data throughput, downstream data
throughput, latency, and/or available air-time. If one or more of
the wireless network parameter exceeds or falls below a threshold,
an alert can be triggered, alerting a network manager, or another
device within the wireless network.
One embodiment of the test device emulating a client device
includes the test device downloading specific web pages. The
performance of the download can be monitored, providing for the
identification of wireless network conditions. The web page can be
selected from a very popular web site because popular web sites
have a greater likelihood of being operational. The test can
include timing how long it takes to download the web page.
For an embodiment, the alert communicates a network condition to
the network manager, so that the network manager is provided with
an opportunity to modify the network to mitigate the network
condition. Alternatively or additionally, the trigger alerts
another device in the wireless network of the network condition.
The other device can modify its operation in an attempt to mitigate
the network condition. For example, a testing device may detect
that a throughput condition or a recently selected route of a
nearby access node is adversely influencing the air-time capacity
available to the testing device. As a result, the nearby device may
be alerted, and the nearby device can modify its throughput or
modify its routing selection in an attempt to mitigate the network
condition.
As previously described, the other wireless device can include a
wireless mesh gateway, a wireless mesh access node or a management
server. The other wireless device can modify wireless network
characteristics to mitigate the network condition. Exemplary
wireless characteristics that can be modified includes, for
example, routing selection, transmission channel selection,
transmission power, transmission bit rate, packet QoS, and/or
dis-associating a client.
Additional intelligence can be included for more precisely relating
the conditions and activities of the wireless network to the
observed or measure network conditions. For example, the test
device can correlate the network condition with other activity of
the wireless mesh network. Activities that can be modified include,
for example, a routing path selection, a device channel selection
and/or a device cluster selection.
In addition to wireless network activities of other devices,
network conditions of other devices can be analyzed. For example,
the test device can correlate the network condition with other
conditions of the wireless mesh network. Exemplary network
conditions include, for example, a device within the wireless
network experiencing heavy loading, a hidden node condition, or
limited availability of air-time.
The hidden node condition includes two wireless devices that are
each able to wirelessly communicate with a third device, but not to
each other. Therefore, each can interfere with the other's wireless
communication with the third device. The test devices (client
and/or access node) can help to identify hidden nodes. Once
identified, the hidden node conditions can be addressed, for
example, by a new route selection, a change in transmit power or a
new channel selection.
FIG. 5 is a flow chart that shows one example of steps of a method
of a network test device sensing a network condition. A first step
510 includes a wireless network test device sensing a wireless
network parameter. A second step 520 includes the wireless network
test device triggering an alert if a wireless network parameter
exceeds or falls below a threshold.
The triggering can be selected to identify situations in which the
measured or monitored wireless network parameter is indicating a
potential wireless network problem. For example, a low receive
signal strength, a low receive signal SNR, a high number of
transmission retries, a low upstream data throughput, a low
downstream data throughput, a high latency, an/or low available
air-time measured at the test device can indicate a problem within
the wireless network. Threshold values for each of these wireless
network parameters can be selected for providing an indication.
The triggered alert can be received by a network operator, or any
device within the wireless network. The receiving device can be,
for example, a device identified by location as the fundamental
contributor of the wireless network condition.
Once a threshold value of at least one of the wireless network
parameters has been detected, the wireless network parameter
exceeding or falling below the threshold can be correlated with a
condition or an activity of another device of the network. That is,
as described, conditions or a recent activity of the other device
within the wireless network could be the source of the detected
problematic wireless network parameter. Therefore, correlating the
problematic wireless network parameter with the condition or
activity of another device can allow mitigation of the problematic
wireless network parameter through modification of operation of the
other device. Once identified, the correlation can be communicated
to the other device. The other device can then modify its operation
to mitigate the observed problematic behavior.
Although specific embodiments have been described and illustrated,
the embodiments are not to be limited to the specific forms or
arrangements of parts so described and illustrated.
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